The present invention relates to a submodule.
With the development of industry and the increase of population, the demand for power has been rapidly increased but there is a limitation in producing power.
Accordingly, a power system for supplying power produced in a production site to a demand site has been gradually important.
The need for facilities, such as a flexible AC transmission system (FACT), has arisen to improve a power flow, a system voltage, and stability. A static synchronous compensator (STATCOME), which is a kind of a power compensation device called a third generation FACT among FACT facilities, is connected to a power system in parallel to compensate for active power and reactive power required in the power system.
FIG. 1 is a view illustrating a typical power system.
As illustrated in FIG. 1, a typical power system 10 may include a power generation source 20, a power system 30, a load 40, and a plurality of power compensation devices 50.
The power generation source 20, which refers to a place or facilities for generating power, may be understood as a producer who produces power.
The power system 30 may refer to all facilities including power lines, steel towers, lightning arresters, insulators, and the like allowing the transmission of the power generated from the power generation source 20 to the load 40.
The load 40, which refers to a place or facilities for consuming the power generated from the power generation source 20, may be understood as a consumer who consumes the power.
The power compensation device 50 may be a device linked to the power system 30 to compensate for relevant reactive power or relevant active power due to the supply or the shortage of the active power or the reactive power of power flowing through the power system 30.
In the case of the power compensation 50, recently, an STATCOM based on modular multilevel converters (MMC) has been increased. The STATCOM based on the MMC includes a plurality of submodules and the submodules are provided therein with various devices.
Accordingly, since a conventional power compensation device has to include a plurality of submodules, the power compensation device may not be installed in a defined space.